A biocompatible adhesive mainly based on human or animal protein is generally prepared in situ by mixing a protein solution with another coagulating solution containing a coagulation factor which promotes coagulation of the protein. When applying to a surgical site the biocompatible adhesive of this kind which, for example, is a mixture of a solution containing both factor XIII and fibrinogen with another solution containing thrombin, one of two following methods are generally used in the art: to apply the first mentioned solution to the surgical site and then coating the same with the second mentioned solution, and to premix the two solutions together before the resultant mixture is applied to the surgical site by the use of a syringe.
These methods suffer from several drawbacks. For example, in the first mentioned method, surface hardening takes place before the two solutions are completely mixed together, which results in insufficient mixing and reduction of the adhesive strength. In the second mentioned method, since the hardening of the adhesive starts soon after mixing the two solutions, it is necessary to apply the adhesive to the surgical site immediately after the mixing. For this reason, this second mentioned method does not only require considerable surgical skill, but also limits its application.
To solve these problems, a method for accommodating those two solutions in syringes separately, ejecting the solutions simultaneously from the respective syringes so as to mix together and apply the resultant mixture to the surgical site, has been suggested in the Japanese Patent Laid-Open Publications No. 64-25843 and No. 64-4040, Japanese Utility Model Laid-Open Publication No. 62-62674, 62-62675, No. 62-65972, No. 62-65973, No. 62-20853, No. 1-82049, and Japanese Utility Model Publication No. 3-47609.
The applicator for applying the biocompatible adhesive described in the Japanese Utility Model Publication No. 3-47609 includes a conflux head having defined therein a pair of conveying channels for conveying two solutions, respectively, which are discharged from associated conical portions, or nozzles of the syringes. The applicator also includes a pair of sterile gas supply channels, which are so arranged in the vicinity of respective outlets of the conveying channels as to lie at a right angle to the conveying channels. Further, the sterile gas nozzles have their longitudinal axes arranged to intersect with each other at a location spaced a specific distance away from the outlets of the sterile gas nozzles.
However, this prior art applicator has the following problems. For example, since the conveying channels lies at substantially right angles to the sterile gas supply channels, that is, they do not direct to the surgical site, if the sterile gas has a low pressure, the adhesive will not be applied properly to the surgical site, or will not be sprayed in uniform density. On the other hand, if the sterile gas of a high pressure is supplied, it may possibly bring about harmful influence upon the surgical site. Also, the distance between the two outlets of the nozzles are so large that these solutions will mix together at a location spaced a distance of about 10 to 20 cm from those outlets. Therefore, the applicator is not available for application of the adhesive to the surgical site which is deep and narrow.
In addition, the sterile gas is introduced through a long tube from a sterile gas supply unit or a cylinder containing a highly pressurized sterile gas. The long tube and/or the cylinder may disturb a surgical job being performed which would cause a loss of surgical operation and a reduction in result of surgical operations.